Tiny Creatures in Water Supply Clogging the Works at Laundries

An unusual abundance of tiny shrimplike crustaceans in city water supplies has brought complaints from managers of some coin-operated laundries in the San Fernando Valley, who say the scaly remains of the creatures are clogging the filters of their washing machines.

Los Angeles water officials said Wednesday that they had received about 15 such complaints earlier this week and, in response, had begun chemically treating the Los Angeles Reservoir in Sylmar, which is the city’s largest water storage lake. The treatment is meant to reduce the buildup of the crumb-size creatures and to eliminate the algae on which they graze.

“We’re doing everything we can to try to get the situation under control,” said Bruce Kuebler, director of water quality for the Los Angeles Department of Water and Power.

The translucent animals are about one-tenth of an inch long. Known as Daphnia or water fleas, they are raised as food for tropical fish. They are also commonly found in fresh water, usually congregating near the surface where sunlight stimulates algae growth.

Water officials said the water fleas pose no health hazard.

For reasons unknown, said Kuebler, the crustaceans are now swimming at greater depths than usual in the 176-acre Sylmar reservoir, and are being sucked into the water distribution system.

When they investigated the laundry operators’ complaints, DWP officials found that the creatures’ skeletal remains were clogging fine screens in the washing machines.

Operators said the clogged filters make the machines fill more slowly, which requires laborious cleaning to fix.

“I’m losing customers,” said Joseph Davis, one of several proprietors of coin-operated laundries who say the infestation is taking them to the cleaners. Davis said the usual 20-minute wash cycle at his Just for You Laundromat in Van Nuys has become a lengthy vigil as customers wait for the machines to fill.

He said he is trying to cope by cleaning the screens daily--”a horrendous job” because some of the screens are hard to get to. “I have 52 machines in my laundry,” he said. “If it averages 10 minutes apiece, we’re looking at a nine-hour job each day.”

Davis said he was sure the same thing is happening in homes, where residents would be likely to conclude that a gradual buildup of sand and grit rather than animals in the water was causing the problem. The average resident would never suspect the true cause of the problem, said Davis, “unless it turns out that he’s just cleaned his screen a week or so earlier.”

Asked whether the creatures could pose a health risk, Kuebler said the only effect might be to cloud water. “The health concern would come from the presence of bacteria, and we use chlorine to ensure there aren’t bacteria that can cause a problem,” he said.

Officials with the drinking water branch of the state Department of Health Services--which regulates water utilities, including the DWP--failed to return telephone calls Tuesday and Wednesday.

But a federal water official said Kuebler’s assessment seemed “reasonable and correct.”

Bill Thurston, chief of the drinking water and ground water protection branch for the Environmental Protection Agency in San Francisco, said, however, that an abundance of the creatures could indicate a need for more chlorine.

Kuebler said DWP crews on Tuesday began feeding chlorine into the reservoir to kill algae and crustaceans. Either today or Friday, workers will also spike the reservoir with crystalline copper sulfate, another chemical widely used to control algae, Kuebler said.

Kuebler said, however, that it could be a few days before the problem disappears.

Ordinarily, it could be fixed by taking the reservoir temporarily out of service and instead using a 12-acre bypass reservoir next to the larger water supply lake. But Kuebler said the bypass reservoir is not available now because the DWP is installing a cover as part of an effort to make smaller water-supply lakes safer.

Ironically, algae growth in the large reservoir has increased in recent years, since the DWP’s Sylmar water filtration plant was brought on line. The plant cleans and purifies aqueduct water from the Owens Valley, but the resulting clarity allows sunlight to penetrate below the water’s surface and to stimulate algae blooms.

To fix the problem, DWP officials are planning to construct a new pipeline and pumping station to filter the water a second time after it leaves the reservoir and before it reaches customers. But that project, which it is estimated to cost $14.5 million, has been deferred as a result of budget cuts.